Braking system



Sept. 19, 1944. H. P. SMITH 2,358,540

. BRAKING SYSTEM Filed Oct. 10, 1942 Patented Sept. 19, 1944 BRAKING srs'rEM Hiram P. Smith, Canton, 111., assignor to International Harvester Company, a corporation of N ew. Jersey Application October 10, 1942, Serial No. 461,553 4 (01. 188-1521) This invention relates to a braking system and more particularly to a' braking system for vehicles, such as tractors.

The invention is concerned particularly with the provision of an improved braking system for agricultural tractors of the type that are operable through varying speed ranges.

In such tractors slow speeds are provided for the operation of the tractor in field work; and the brakes are so arranged as to be capable of applicationto either one oi. the rear wheels, de-

. pending upon the direction in which the tractor is turned. This arrangement provides the usual form of steering assisted by braking.

Most tractors of the type referred to are without provision for the eil'ecting of any change in the ordinary braking arrangement; with the rewheels II and H. The body I0 includes 'a transmission housingv iii in which is enclosed drive means for the traction wheels, this drive means further including a transverse countershaft with which is associated a pair of brakes for the wheels. As shown in Figure 1, these brakes are respectively housed in brake housings i4 and l5,

' one at each side of'the tractor body l0.

sult that the brakes may be similarly operated during high speed travel of the tractor. vIt has been found that this presents a decided hazard,

since the application of the brakesindependently 1 duringrhigh speed travel of the tractor can result inupsetting of the tractor and consequent injury to the operator.

Theprincipal object of. the present invention is to provide an improvedbraking system incorporating safety means enabling the simultaneous operation of the tractor brakes so that dangers during high speed travel of the tractor are eliminated or at least minimized. e

An important object of therinvention is to.. r

adapt the. improved safety means to a hydraulic braking system.

Another object of the invention is to provide a braking system having a pair of pedal-operated, independently'actuatable brakes, by means of which the usual form of brake-assisted steering may be accomplished, and to incorporate aconnection between the brakes having means by which this connection may be controlled to provide for simultaneous application of the tractor brakes.

ently operable and each hasits' own. operating Other important objects and desirable features of the invention may be had from the following detailed description taken in conjunction with the accompanying sheet of drawings, in which:

Figure 1 is a plan view of the rear portion of a tractor, illustrating generally the braking arrangement; and j Figure 2 is a view showing schematically one form of the braking system.

The tractor chosen for the purposes or illustration is representative of the usual form of ag- 4 ricultural tractor and is shown as including a body l0 "carried on right and left rear traction One side of the tractor body is provided with means carrying a pair of brake pedals l6 and II,

which; as will be hereinafter described, are adapted for the independent operation of the braking mechanism contained in thebrake housings l4 and I 5.

As best shown in Figure 2,. the right-hand brake pedal I8 is connected to a master hydraulic cylinder I8, which may be of any conventional form. The left-hand brake pedal Ills connected to a similar cylinder IS. .The cylinder I8 is connected by a conduit 26 to a brake-operating cylinder 2| associated with brake-mechanism 22 for the right-hand traction wheel II. The brake mechanism may be 01' any conventional form.

I The cylinder 19 is'connected by a conduitj23 to a brake-operating cylinder 24 for brake mechanism 25 for the left-hand traction wheel I2.

The brake mechanisms 22 and 25 are respectively housed in the brakejhousings 'l4 and I5.

From the description thus far, it will'be seen that pressure on the brake pedal l6 will result in.

the applicatlgn of the; brake on the right-hand traction wheel Ii, and that similar results follow with respect to the leit -handtractionwheel l2 uponoperation of the left-hand brake, pedal 11. 5 Q

Itwill be noted that the brakes are-independmeans, such as the pedals l6 and i1. It has heretofore pedals at once. In some cases, provision has been made inthe. form of latch means fo'rlqcking the pedals together. However, "ne'ither"'sys-- tem has proved effective.

According to' the present invention, means-are provided for connecting the brake mechanisms 1 for simultaneous operation. This means in cludes a conduit cross-connecting the fluid lines 20 and23. The conduit 26 includes a rotat-- able valve 21 contained in a housing 28 and having a passage 28 therein adapted to connect passages 30 and 3| formed in the valve housing 28 and in communication with opposite sides of the 7 been common practice in j braking systems similar to that disclosed to tie-.- L

pend for simultaneous application of the brakes upon the ability of the operatorto depress both" cross-connecting conduit 26. This valve may be operated by a control lever 32.

In the operation of the tractor for ordinary field purposes, during which the tractor is run slowly, the valve 21 is positioned, as shown in Figure 2, so that the conduit 26 is blocked against the passage of fluid therethrough. Accordingly,

the pedals l6 and Il may be actuated for independent operation of the brake .mechanisms 22 and 25, and the usual result of brake-assisted steering may be obtained. When the tractor is to be operated at higher speeds, in which circumstances independent braking would be dangerous, the operator rotates the valve 21 by means of the handle 32 so that the passage 29 in the valve cross-connects the passages 30 and 3| in the valve housing. There is thus provided a free communication between the conduits 20 and 23 sothat application of either of the brake pedals I5 and I1, or both, results inthe forcing of fluid under equal pressure to both of the brake mechanisms 22 and 25, with the result that the traction wheels II and H are braked simultaneously.

It will thus be seen that the invention provides means by which independently operable brakes may be connected together for simultaneous operation, and that the use of such means in the operation. It will be understood, of course, that the foregoing description pertains to only one form of the invention, and that the invention may be embodied in several forms without departing from the spirit and scope thereof, as defined in the appended claims. a

What is claimed is:

1. In a braking system for tractors having a pair of traction wheels, an independent brake for each of said wheels, separate hydraulic actuating means for each of said brakes, separate pedal-operated means for supplying actuating fluid under-pressure to each said-actuating means including independent conduits, means including an interconnecting conduit providing a free communication between said conduits for the flow of the actuating fluid during certain phases of tractor operation, and means for blocking said interconnecting conduit during certain other phases of tractor operation.

2. In a, braking system for tractors having a pair of traction wheels and an independent brake for each of said wheels, separate hydraulic actuating means for each of said brakes, separate pedal-operated means for supplying fluid under pressure to each said actuating means including independent conduits, conduit means providing a communication between said conduits, and valve means selectively operable to provide for either the blocking of the conduit means or for the flow of. the actuating flui through said conduit means.

4. In a braking system for tractors having a pair of traction wheels and an independent brake for each of said wheels, hydraulic actuating means for each of said brakes, independent pedaloperated means for supplying fluid under pressure to each of said actuating means including independent conduits, conduit means providing a communication between said conduits for sup plying fluid under uniform pressure to each said brake upon actuation of only one 'said pedaloperated means, and valve means selectively operable to provide for either the blocking of the conduit means or for the fiow of the actuating fluid through said conduit means.

HIRAM P. SMITH. 

